• Journal of Mechanical Science and Technology
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• v.16 no.9
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• pp.1102-1111
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• 2002

The study focuses on the heat transfer performance of two-phase closed thermosyphons with plain copper tube and tubes having 50, 60, 70, 80, 90 internal grooves. Three different working fluids(distilled water, methanol, ethanol) are used with various volumetric liquid fill charge ratio from 10 to 40%. Additional experimental parameters such as operating temperature and inclination angle of zero to 90 degrees are used for the comparison of heat transfer performance of the thermosyphon. Condensation and boiling heat transfer coefficients, heat flux are obtained using experimental data for each case of specific parameter. The experimental results are assessed and compared with existing correlations. The results show that working fluids, liquid fill charge ratio, number of grooves and inclination angle are very important factors for the operation of thermosyphons. The relatively high rate of heat transfer is achieved when the thermosyphon with internal grooves is used compared to that with plain tube. The optimum liquid fill charge ratio for the best heat transfer performance lies between 25% and 30%. The range of the optimum inclination angle for this study is 20$^{\circ}$～30$^{\circ}$ from the horizontal position.

• Journal of Mechanical Science and Technology
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• v.19 no.12
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• pp.2296-2302
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• 2005

This study is focused on the comparison of heat transfer performance of two thermosyphons having 60 straight and helical internal grooves. Distilled water has been used as working fluid. Liquid fill charge ratio defined by the ratio of working fluid volume to total internal volume of thermosyphon, the inclination angle and operating temperature were used as experimental parameters. The heat flux and heat transfer coefficient are estimated from experimental results. The conclusions of this study may be summarized as follows; Liquid fill charge ratio, inclination angle and geometric shape of grooves were very important factors for the operation of thermosyphon. The optimum liquid fill charge ratio for the best heat flux were $30\%$. The heat transfer performance of helically grooved tube was higher than that of straight grooved tube in low inclination angle (less than $30^{\circ}$), but the results were opposite in high inclination angle (more than $30^{\circ}$). As far as optimum inclination angle concerns, range of $25^{\circ}\~30^{\circ}$ for a helically grooved tube and about $40^{\circ}$ for a straight grooved tube are suggested angles for the best results.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.55-60
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• 1993

This study was performed to investigate the effect of washing with water and detergent on the vitamin C content in strawberry and perilla leaf. Vitamin C was extracted with the solution of metaphosphoric acid and quantitated by high performance liquid chromatograph (HPLC). There was no significant difference of vitamin C content between the washing with distilled water and tap water. Three available detergents reduced the vitamin C content of samples to 92.5%, 92.2% and 78.5%, respectively. The content of vitamin C in samples was decreased by increasing the concentration of detergent and washing time.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.197-203
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• 2014

Various parameters such as solvent selection, concentration, solid/liquid ratio, soaking time, temperature, stationary, shaking conditions, and repeated extractions were investigated in order to determine the optimum extraction conditions of ${\beta}$-glucosidase from bagasse fermented by mixed culture of Aspergillus niger NRC 7A and Aspergillus oryzae NRRL 447. Among various solvents tested, non ionic detergents gave the best results than the inorganic or organic salt solutions and distilled water. The optimum conditions for extraction of ${\beta}$-glucosidase were 30 min soaking time at $40^{\circ}C$ under shaking condition at 150 rpm, with solid/liquid ratio 1:15 (w/v), which yielded $2882.74{\pm}95.52U/g$ fermented culture (g fc) of enzyme activity. With repeated washes under the above optimum conditions, the results showed that enzyme extracted in the $1^{st}$ and $2^{nd}$ washes represents about 90% of the total activity.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.261-266
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• 1998

A method for the determination of noboviocin in milk was presented by high performance liquid chromatography(HPLC). The novobiocin in the spiked sample was extracted with methanol and evaporated under vacuum. After evaporating, the residue was mixed with distilled water for 2$m\ell$, filtrates with 0.45$\mu\textrm{m}$ acrodisc was injected into HPLC. The results obtained were as follows ; 1. The calibration curve of novobiocin was showed constantly linear(r 0.999) in the range of 100~500ng/$m\ell$. 2. The mean recovery rate of novobiocin from the spiked milk sample were 88~98%. 3. The coefficients of variation were 2.6~5.8% 4. The lowest detectable limit of novobiocin was 25ppb.

• Korean Journal of Optics and Photonics
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• v.2 no.1
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• pp.1-6
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• 1991

This paper describes the theoretical analysis of a diffraction pattern analyzer for the characterization of microscale object fields and a method for obtaining size and size distribution from the measured diffraction pattern of the object fields. For the experimental verification, a typical optical Fourier transform system was set up and calibrated with 2 5$\mu \textrm m$ and 50$\mu \textrm m$ pinholes. The system responses to distilled water droplets, alcohol, glycerin and silicon oil were imaged with vidicon, and the image was processed to determine the size distribution of each liquid particle field. The energy distribution function which is defined as the total intensity of a circular ring in the diffraction pattern was used to determine the dominant particle size of each liquid particle field.

• Journal of the Korean Ceramic Society
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• v.30 no.8
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• pp.623-628
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• 1993

Lead monoxide has two phases at room temperature. One is a yellow orthorhombic phase, the other is a redtetragonal phase. Sometimes two phases are hybrided. The specificity of phase transitions of lead oxide is found during the milling of the batch including lead oxide. The pure orthorhombic phase of PbO can be transformed to the tetragonal phase perfectly by wet ball milling (milling liquid is distilled water) without thermal energy. However, when ethyl alcohol, isopropyl alcohol and aceton are used as milling liquid, respectively, the hybrid form of orthorhombic andtetragonal phases is obtained by wet ball milling. From the hybrid form heat-treated at $600^{\circ}C$ for 3hrs, this work results that mechanical phase transition of orthorhombic phase make a new form as distorted type orthorhombic phase of PbO.

• Journal of Fashion Business
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• v.13 no.3
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• pp.109-117
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• 2009

To set up the outstanding and scientific dyeing method in making the condensed liquid of pigment obtained from onion skins and the improved reliability, the following basic experiments were performed. The pigment was extracted in the distilled water at $70^{\circ}C$ and methanol at room temperature and then it was analyzed with LC/MS/MS system (Liquid Chomatography/Mass Spectroscopy/Mass Spectroscophy, LIQ Advantage Max, Thermo Finnigan, USA) for its pigmental characteristics. The unrefined silk and refined silk were dyed by making use of the derived pigment in such a way. The chromameter (CR-200, Minolta, Japan) was used to measure the change in surface color in textiles to be dyed by the extracting condition and the color difference ${\Delta}E$ was determined according to the color difference formula CIE LAB through measuring the psychometric lightness L* and chromaticity coordinates a* and b*.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2019.05a
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• pp.69-69
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• 2019

The distillation of liquid cathode is necessary to separate cadmium from the actinide elements in the pyroprocessing since the actinide deposits are dissolved or precipitated in a liquid cathode. It is very important to avoid a splattering of cadmium during evaporation due to the high vapor pressure. Several methods have been proposed to lower the splattering of cadmium during distillation. One of the important methods is an installation of crucible cover on the distillation crucible. A multi-layer porous round cover was proposed to avoid a cadmium splattering in our previous study. In this study, the effect of crucible cover on the cadmium distillation was examined to develop a splatter shield. Various surrogates were used for the actinides in the cadmium. The surrogates such as bismuth, zirconia, and tungsten don't evaporate at the operational temperature of the Cd distiller due to their low vapor pressures. The distillation experiments were carried out in a crucible equipped with cover and in a crucible without cover. About 40 grams of Cd was distilled at a reduced pressure for two hours at various temperatures. The mixture of the cadmium and the surrogate was heated at $470{\sim}620^{\circ}C$. Most of the bismuth remained in the crucible equipped with cover after distillation under $580^{\circ}C$ for two hours, whereas small amount of bismuth decreased in the crucible without cover above $580^{\circ}C$. The liquid bismuth escaped with liquid cadmium drop from the crucible without cover. It seems that the crucible cover played a role to prevent the splash of the liquid cadmium drop. The effect of the cover was not clear for the tungsten or zirconia surrogate since the surrogates remained as a solid powder at the experimental temperature. From the results of this work, it can be concluded that the crucible cover can be used to minimize the deposit loss by prevention of escape of liquid drop from the crucible during distillation of liquid cathode.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.101-107
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• 1997

Phellinus linteus was artificially cultivated in kangwon province in Korea. The air-dried phellinus linteus was frozen in liquid nitrogen tank and powdered in jar. 10g of the powder was extracted with each 200g of ethanol, methanol, distilled water and 1,3-butylene glycol/distilled water 4 hours under refluxing and then the liquidextract was concentrated under reduced pressure. As a result of analysis by high performance liquid chromatography and thin layer chromarography, many kinds of sugar and flavonoids were detected. Also we knew that phellinus linteus' extract had a strong UV-ray absorption. In the efficacy test for applying to cosmetics, free radical scavenging effect was confirmed. As a result, 2% of sample was the most potent inhibitory effect and the free radical savenging activity, was 0.31%. This is more effective than any other meterial. In the test of antioxidative activity against lipid autoxidation, phellinus linteus' extract had a good effect by 46% while vitamine E was 42.3%. The immunological activity of phellinus linteus was showed through the activation of macrophage cell. Actually, phellinus linteus activated macrophage function of 1.1-1.8 times including nitrite production compared to control. The whitening effect of phellinus linteus was showed through the inhibition of tyrosinase activity, melanin biosynthesis of S. bikiniensis and B-16 melanoma cells. Phellinus linteus' extract was showed strong mushroom tyrosinase inhibitory activity with IC50 value of 0.5% and inhibited melanin biosynthesis with 28mm inhibition zone at 0.005%/paper disc in S. bikinniensis, a bacterium used as an indicator organism in this work. Also it inhibited melanin biosynthesis in B-16 melanoma cells with a minimum inhibitory concentration of 0.134%.